lnrpc+rpcserver: add payment_addr field to PayReq

lnrpc/rpc.proto

@@ -2615,6 +2615,7 @@ message PayReq {
     string fallback_addr = 8 [json_name = "fallback_addr"];
     int64 cltv_expiry = 9 [json_name = "cltv_expiry"];
     repeated RouteHint route_hints = 10 [json_name = "route_hints"];
+    bytes payment_addr = 11 [json_name = "payment_addr"];
 }
 
 message FeeReportRequest {}

lnrpc/rpc.swagger.json

@@ -3248,6 +3248,10 @@
           "items": {
             "$ref": "#/definitions/lnrpcRouteHint"
           }
+        },
+        "payment_addr": {
+          "type": "string",
+          "format": "byte"
         }
       }
     },